// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <unordered_set>

#include "gtest/gtest.h"
#include "src/reader/wgsl/parser.h"
#include "src/writer/wgsl/generator.h"

namespace tint {
namespace ast {
namespace {

TEST(ModuleCloneTest, Clone) {
#if TINT_BUILD_WGSL_READER && TINT_BUILD_WGSL_WRITER
  // Shader that exercises the bulk of the AST nodes and types.
  // See also fuzzers/tint_ast_clone_fuzzer.cc for further coverage of cloning.
  Source::File file("test.wgsl", R"([[block]]
struct S {
  [[size(4)]]
  m0 : u32;
  m1 : array<u32>;
};

let c0 : i32 = 10;
let c1 : bool = true;

type t0 = [[stride(16)]] array<vec4<f32>>;
type t1 = array<vec4<f32>>;

var<private> g0 : u32 = 20u;
var<private> g1 : f32 = 123.0;
[[group(0), binding(0)]] var g2 : texture_2d<f32>;
[[group(1), binding(0)]] var g3 : texture_storage_2d<r32uint, read>;
[[group(2), binding(0)]] var g4 : texture_storage_2d<rg32float, write>;
[[group(3), binding(0)]] var g5 : texture_storage_2d<r32uint, read>;
[[group(4), binding(0)]] var g6 : texture_storage_2d<rg32float, write>;

var<private> g7 : vec3<f32>;
[[group(0), binding(1)]] var<storage, write> g8 : S;
[[group(1), binding(1)]] var<storage, read> g9 : S;
[[group(2), binding(1)]] var<storage, read_write> g10 : S;

fn f0(p0 : bool) -> f32 {
  if (p0) {
    return 1.0;
  }
  return 0.0;
}

fn f1(p0 : f32, p1 : i32) -> f32 {
  var l0 : i32 = 3;
  var l1 : f32 = 8.0;
  var l2 : u32 = bitcast<u32>(4);
  var l3 : vec2<u32> = vec2<u32>(u32(l0), u32(l1));
  var l4 : S;
  var l5 : u32 = l4.m1[5];
  let l6 : ptr<private, u32> = &g0;
  loop {
    l0 = (p1 + 2);
    if (((l0 % 4) == 0)) {
      continue;
    }

    continuing {
      if (1 == 2) {
        l0 = l0 - 1;
      } else {
        l0 = l0 - 2;
      }
    }
  }
  switch(l2) {
    case 0u: {
      break;
    }
    case 1u: {
      return f0(true);
    }
    default: {
      discard;
    }
  }
  return 1.0;
}

[[stage(fragment)]]
fn main() {
  f1(1.0, 2);
}

let declaration_order_check_0 : i32 = 1;

type declaration_order_check_1 = f32;

fn declaration_order_check_2() {}

type declaration_order_check_2 = f32;

let declaration_order_check_3 : i32 = 1;

)");

  // Parse the wgsl, create the src program
  auto src = reader::wgsl::Parse(&file);

  ASSERT_TRUE(src.IsValid()) << diag::Formatter().format(src.Diagnostics());

  // Clone the src program to dst
  Program dst(src.Clone());

  ASSERT_TRUE(dst.IsValid()) << diag::Formatter().format(dst.Diagnostics());

  // Expect the AST printed with to_str() to match
  EXPECT_EQ(src.to_str(), dst.to_str());

  // Check that none of the AST nodes or type pointers in dst are found in src
  std::unordered_set<ast::Node*> src_nodes;
  for (auto* src_node : src.ASTNodes().Objects()) {
    src_nodes.emplace(src_node);
  }
  std::unordered_set<sem::Type*> src_types;
  for (auto* src_type : src.Types()) {
    src_types.emplace(src_type);
  }
  for (auto* dst_node : dst.ASTNodes().Objects()) {
    ASSERT_EQ(src_nodes.count(dst_node), 0u) << dst.str(dst_node);
  }
  for (auto* dst_type : dst.Types()) {
    ASSERT_EQ(src_types.count(dst_type), 0u) << dst_type->type_name();
  }

  // Regenerate the wgsl for the src program. We use this instead of the
  // original source so that reformatting doesn't impact the final wgsl
  // comparison.
  std::string src_wgsl;
  {
    writer::wgsl::Generator src_gen(&src);
    ASSERT_TRUE(src_gen.Generate()) << src_gen.error();
    src_wgsl = src_gen.result();

    // Move the src program to a temporary that'll be dropped, so that the src
    // program is released before we attempt to print the dst program. This
    // guarantee that all the source program nodes and types are destructed and
    // freed. ASAN should error if there's any remaining references in dst when
    // we try to reconstruct the WGSL.
    auto tmp = std::move(src);
  }

  // Print the dst module, check it matches the original source
  writer::wgsl::Generator dst_gen(&dst);
  ASSERT_TRUE(dst_gen.Generate());
  auto dst_wgsl = dst_gen.result();
  ASSERT_EQ(src_wgsl, dst_wgsl);

#else  // #if TINT_BUILD_WGSL_READER && TINT_BUILD_WGSL_WRITER
  GTEST_SKIP() << "ModuleCloneTest requires TINT_BUILD_WGSL_READER and "
                  "TINT_BUILD_WGSL_WRITER to be enabled";
#endif
}

}  // namespace
}  // namespace ast
}  // namespace tint